Jeronimo Martins' shares could jump 20% to 30% in 2014 as its Polish discount grocer Biedronka hits a sweet spot in the sector.

Polish discount grocer Biedronka is going cheap. Shares of the grocer's Portuguese parent, Jeronimo Martins SGPS (ticker: JMT.Portugal), are at their lowest in over a year. Even with the margin-pinching investment needed to ride out a highly competitive environment in Poland, Jeronimo Martins has lots of room to grow.